Tappet turning-prevention structure for fuel supply apparatus

Abstract

A tappet turning prevention structure for a fuel supply apparatus includes a piston defining a fuel pressurizing chamber within the housing. A tappet disposed at one end of the piston has accommodated in it a roller driven by a cam of an engine and a roller supporting pin for transmitting a force from the cam to the piston. The tappet is housed by a bracket which has one or two grooves in an inner surface of it for supporting the roller supporting pin at one or both ends. The number of parts can be decreased because the turning prevention pin for the tappet and the roller supporting pin is a single common pin, and therefore the need of controlling of the press-fit loads is eliminated because no process for thrusting the tappet turning prevention pin into the outer circumference of the tappet is involved.

What is claimed is:  
     
       1. A tappet turning prevention structure in a fuel supply apparatus comprising: 
       a casing having formed therein a suction passage through which fuel is sucked in, a discharge passage through which fuel is discharged and a cylindrical concaved housing section;  
       a sleeve having a cylinder-shaped cylindrical section and a flange-shaped mounting section disposed at one end of the cylindrical section, said sleeve being disposed with one end of the mounting section abutting against the bottom of said concaved housing section;  
       a piston disposed within said cylindrical section in a manner allowing its reciprocating motion and defining a fuel pressurizing chamber together with said cylindrical section;  
       a tappet disposed at one end of said piston opposite to said fuel pressurizing chamber and having accommodated therein a roller driven by a cam of an engine and a roller supporting pin for rotatably supporting said roller for transmitting a force of said cam to said piston; and  
       a bracket fastened to said casing and housing said tappet for allowing a reciprocating motion of said tappet;  
       wherein said bracket has a groove in an inner surface thereof for allowing an end portion of said roller supporting pin to engage therein.  
     
     
       2. A tappet turning prevention structure of a fuel supply apparatus as claimed in  claim 1 , wherein said bracket has two grooves in an inner surface thereof for allowing end portions of said roller supporting pin to engage at positions opposite to each other.